Headphones, personal monitors, in-ear monitors, earphones, earbuds and hearing aids are a pair of loudspeakers that are configured to be positioned close to a user's ear drums or in a user's ear canal with a means for connecting them psycho-acoustically to an audio source. Headphones are commonly used with electronic equipment such as CD or DVD players, home theater systems, personal computers, as well as portable electronic devices such as portable music players, mobile phones, and so forth. Wired headphones attach to the audio source and typically use a common connector known as a stereophonic jack to be connected to the audio source. Some headphones fit over the outer portion of a user's ear and other headphones are designed to fit within an outer part of the ear canal of the user. In addition, some are designed to fit in the ear canal close to the ear drum. Headphones that are designed to fit within the outer part of the ear canal are commonly referred to as earbuds and headphones which occlude and reside in the ear canal are considered in ear monitors, personal monitors and canal phones.